SIST EN 1424:1999/A1:2004

Overview

EN 1424:1997/A1:2003 - "Road marking materials - Premix glass beads" (CEN) defines laboratory product control and qualification procedures for premix glass beads used in road marking materials. The amendment A1 (approved 2 Jan 2003, published April 2003) updates EN 1424:1997 and clarifies test references and acceptance criteria. The standard covers properties such as granulometry, refractive index, chemical resistance, quality, and surface treatments, but excludes glass beads used solely as filler in marking products.

Key Topics and Requirements

• Scope: requirements apply to premix glass beads incorporated in road marking materials; filler-use beads are excluded.
• Laboratory testing (product control) and qualification procedures to verify bead performance and conformance.
• Physical and optical properties addressed:
  • Granulometry - particle size distribution described using sieves (ISO 565 sizes R 40). A transitional allowance permits some national granulometries for five years after publication.
  • Refractive index of the glass - ensures retroreflective performance when embedded in markings.
  • Chemical resistance - resistance to binder components and environmental exposure.
  • Surface treatments - coatings or treatments that affect bead adhesion and durability.
  • Quality and defects - methods to identify imperfections (Annex C) and to classify defective beads.
• Defect limits (reference method): Table values in the amendment set maximum weighted percentages for grains/foreign particles and defective beads by bead diameter (reference/normative test in Annex D). In disputes, Annex D of EN 1423:1997 is the reference method.
• Alternative test methods allowed if correlated (see EN 1423 Annex H), but the reference (normative) method remains the final arbiter in disagreements.

Applications and Users

• Practical use: ensures consistent optical performance, durability and safety of road markings (paint, thermoplastic, premix systems).
• Primary users:
  • Road marking material manufacturers and formulators
  • Raw material suppliers of premix glass beads
  • Quality control and testing laboratories
  • Highway authorities and transportation departments specifying material acceptance criteria
  • Certification and compliance bodies in Europe
• Benefits: improves retroreflectivity, adhesion, longevity of markings, and provides reproducible test methods for procurement and conformity assessments.

Related Standards

• EN 1423:1997 (Drop-on materials - Glass beads, antiskid aggregates and mixtures) - referenced normative document; Annex D is the reference test method and Annex H provides correlated alternative methods.
• ISO 565 - sieve sizes (R 40) used for granulometry descriptions.

Keywords: EN 1424:1997/A1:2003, premix glass beads, road marking materials, granulometry, refractive index, product control, CEN standard, glass bead defects, Annex D reference method.